A Speed Control Lubrication Improvement Idea

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SteveMaryland
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A Speed Control Lubrication Improvement Idea

Post by SteveMaryland »

Just about all of the failures on my Shopsmith (aside from operator deficiency) have been in the sliding-sheave speed control system. Lubrication is the key to smooth operation and longevity here, as I think most will agree.

I believe the current 2-hole drip lubrication is marginal. Difficult to access, and Insufficient oil gets into and stays in the journal where it is needed. And this drip-lube system also leads to oil spillage on the belt and elsewhere.

Oil grooves in the control sheave bore and in the bore of the floating sheave (on the motor) would aid in distributing the oil across the journals. Forget about SS incorporating them.

A related improvement would be to route filtered air into the headstock for positive pressure - thus keeping out all the sawdust currently sucked into and through the headstock by the motor fan and thus contaminating oiled surfaces as currently. Another SS design deficiency.

See attached figure. The idea is to add a washer-shaped pad of industrial felt wick (or equivalent synthetic absorbent material) into the cavity shown. Wick size would need to be large enough to hold oil but small enough to not interfere with operation. This wick would act as a long-term oil reservoir. An additional oil hole would be needed to soak the wick, and this hole would also serve as a breather vent when the sheaves are opened/closed (which is a feature that might be beneficial in and of itself).

Oil wicks were and are used in industrial machinery, and also bushing oil grooves, so these are nothing new. But the wick idea would be easy to try out.

Anyway, I just finished another rebuild and am not going to tear things apart again just to add this wick, but I thought I would post this idea for someone else to try.

Another idea: attach the washer-shaped wick to the end of the shaft - then the wick will wipe the bore with oil every time the speed is adjusted.
Attachments
CONTROL AND IDLER SHEAVE OIL WICK ADDITION.JPG
CONTROL AND IDLER SHEAVE OIL WICK ADDITION.JPG (136.53 KiB) Viewed 5735 times
Mark V, Model 555510, Serial No. 102689, purchased November 1989. Upgraded to 520
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JPG
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Re: A Speed Control Lubrication Improvement Idea

Post by JPG »

It would also aid in keeping the button bearing lubricated.

?? how much space is there between the end of the idler shaft and button bearing at "low"?

Too bad it will not work on the floating sheave(which is where major stickiness occurs).
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
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SteveMaryland
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Re: A Speed Control Lubrication Improvement Idea

Post by SteveMaryland »

The button bearing would not be affected by this mod because it is sealed.

The minimum space is approximately as shown but I did not have the shaft available for modeling so the space shown is an estimate. Not much space at minimum.

As for the floating sheave, we could install a thin cylindrical wick that would fit in the space between hub and spring, and cover the oil hole. The idea would be to keep the oil hole replenished by saturating the wick. For that application, would need to use a porous rigid plastic material (like that used in sharpie-type pen nibs) instead of a felt wick because a felt wick likely would be torn up by the spring.
Mark V, Model 555510, Serial No. 102689, purchased November 1989. Upgraded to 520
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JPG
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Re: A Speed Control Lubrication Improvement Idea

Post by JPG »

IIRC the button bearing is shielded, not sealed.
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
RFGuy
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Re: A Speed Control Lubrication Improvement Idea

Post by RFGuy »

SteveMaryland wrote: Sun Jun 12, 2022 1:41 pm A related improvement would be to route filtered air into the headstock for positive pressure - thus keeping out all the sawdust currently sucked into and through the headstock by the motor fan and thus contaminating oiled surfaces as currently. Another SS design deficiency.
Steve,

Yeah, this is a good idea and has been done. Check out my post on this a while back below. Geoffrey Baker posted his solution for adding filtered positive air displacement to his PowerPro headstock for cooling purposes but it could be used on any headstock to minimize dust infiltration. I have been meaning to do this to mine, but just haven't gotten to it yet...

viewtopic.php?p=266628#p266628
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Mark V 520 (Bought New '98) | 4" jointer | 6" beltsander | 12" planer | bandsaw | router table | speed reducer | univ. tool rest
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SteveMaryland
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Re: A Speed Control Lubrication Improvement Idea

Post by SteveMaryland »

Just saw the Baker video on YouTube (https://www.youtube.com/watch?v=USWBJjkQQGI). He has the right idea.

Why is Shopsmith not offering such a retrofit blower setup or at least a kit which would allow ducting of shop vac exhaust air into the headstock? Especially now that PowerPro is having sensor dust fouling problems?

My concern was that dust fouling was aggravating the lube problem by soaking up oil + gumming up oiled surfaces. Creating positive pressure improves the dust/lube contamination problem, improves motor cooling, and addresses the PPro sensor fouling problem as well. Significant improvements but Shopsmith offers nothing.

What many users may not realize is that the current centrifugal cooling blower on the motor creates a negative-pressure condition in the headstock which causes dust to be drawn in from everywhere. So a successful retrofit setup must supply a CFM equal to that blower + additional CFM, in order to create a net positive-pressure condition. That is a lot of CFM. I don't know what that CFM would be and I don't know if Baker's setup has achieved it.

A well-designed engineered retrofit solution from Shopsmith would be something I would buy. Without it we are stuck with jerry-rig and that is unfortunate considering the benefits.
Mark V, Model 555510, Serial No. 102689, purchased November 1989. Upgraded to 520
RFGuy
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Re: A Speed Control Lubrication Improvement Idea

Post by RFGuy »

Steve,

I agree. I wish that Shopsmith offered more products, updated products, new accessories, etc., etc. Unfortunately I don't think this is very likely. I could be wrong, but I think they only have one engineer on staff. I am sure he is quite busy with sustaining engineering work in support of manufacturing which likely takes most of his time. This is NOT an easy task as Shopsmith continues to support many legacy products with countless manufacturing tweaks over many decades. This is why a lot of companies drop support for legacy products after "x" years. It does seem like they are trying to offer some upgraded products in recent years, e.g. the updated DC-3300 is just one example. I'd really like to see an updated PowerPro, but that is just me. Whatever Shopsmith brings out in the future, I wish them all the best...
📶RF Guy

Mark V 520 (Bought New '98) | 4" jointer | 6" beltsander | 12" planer | bandsaw | router table | speed reducer | univ. tool rest
Porter Cable 12" Compound Miter Saw | Rikon 8" Low Speed Bench Grinder w/CBN wheels | Jessem Clear-Cut TS™ Stock Guides
Festool (Emerald): DF 500 Q | RO 150 FEQ | OF 1400 EQ | TS 55 REQ | CT 26 E
DC3300 | Shopvac w/ClearVue CV06 Mini Cyclone | JDS AirTech 2000 | Sundstrom PAPR | Dylos DC1100 Pro particulate monitor
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SteveMaryland
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Re: A Speed Control Lubrication Improvement Idea

Post by SteveMaryland »

Another thought about cooling air routing through the Mark V headstock. We know that the motor fan creates a low air pressure condition inside the headstock, and all during headstock operation dusty air is sucked in through seams etc., through the motor, and out the exhaust port under the headstock. An old problem, but we would rather have a dust-free interior because we have exposed oiled components inside, and sawdust inevitably piles up on oiled surfaces. And on the Power Pro, dust piles up on the optical sensors, or so I hear.

Use of graphite dry lube may reduce the dust-adhesion problem but we really cannot use graphite everywhere inside the headstock.

What if we replaced the item 46 nameplate with an air filter? This would not eliminate all dust entry, but I think it would reduce it substantially. Because, if we have a 3-1/4" diameter (that's the nameplate hole size) filter mounted where the nameplate is currently, most of the cooling air pulled in by the motor would then come in through this filter (because it would now be the path of least air resistance), and it would be filtered air.

A simple mod which may result in a cleaner headstock interior.
Mark V, Model 555510, Serial No. 102689, purchased November 1989. Upgraded to 520
DLB
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Re: A Speed Control Lubrication Improvement Idea

Post by DLB »

I have always assumed that the primary air inlet to the conventional (non-PowerPro) headstock is the vent plate (Item 101) installed in the belt cover around the Idler. Supplemented, of course, by unsealed seams and gaps elsewhere. And I've presumed this to be deliberate design, most of the cooling air enters at the Idler, cooling it, and exits through the motor. Thus cooling two major heat sources. Allowing a lot of air to enter elsewhere may reduce the cooling in the Idler vicinity. If I were going to try this mod, I would instrument or monitor the case temperature near the Idler just to see what happens before going all in. A simple test could be done by monitoring this temp with/without the nameplate to ensure the mod would not take too much cooling away from the Idler.

That's just my two cents. I'm all PowerPro now and I find Idler life/longevity to be an annoyance. PowerPro doesn't pull much air in through the vent, if any. I suspect it exhausts through it. But it's not a level playing field due to the new style Idler bearings, different belts, and the higher speeds the Idler is occasionally (rarely in my case) exposed to.

- David
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SteveMaryland
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Re: A Speed Control Lubrication Improvement Idea

Post by SteveMaryland »

I agree about the 101 vent plate. I would not want this mod to starve the idler bearing for cooling air. So if I pursued this mod I would need to also modify or replace 101 with something having the same or lower air resistance + a (flat) filter.

It would be desirable for the same or similar filter element to fit both locations. Maybe a replaceable round coffee filter would work.

Problem with flat filters is they fill up rapidly, and these would likely need to be vacuumed clean or replaced after each headstock use.
Mark V, Model 555510, Serial No. 102689, purchased November 1989. Upgraded to 520
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